Scope: The three-phase power path for the compressor: 460 V plug → CB1 → CS → PA/PB phase contactors → CH compressor contactor → CP motor.. The compressor is the main load of the unit, and this path is the drawing's main power train.
Boundary: Source = 460-3-60 / 380-3-50 power plug; sink = compressor motor CP.. The plug is where external power enters the unit. The compressor is the critical load.
Can fail: source, breaker, ct, sink. Breaker CB1, the contactors (PA, PB, CH), the current sensor in the line conductors, the supply plug and the compressor motor are discrete parts that can fail. Wiring and terminal blocks are treated as perfect connectors.
Success: any_path. The compressor runs when any closed three-phase path goes from the plug to the motor. PA and PB are alternative phase-sequence contactors that both feed the CH line terminals.
Not modelled:
- Control circuit (TR transformer, controller, coil supplies, sensors): Control logic and coil power can't be expressed as a power-path graph from this sheet.
- Fan, heater and pump motor branches (CF/ES/EF/HR contactors, EM1/EM2, CM, heaters): Left out to keep the model to the compressor power path.
- 230/190 V autotransformer (DVM/TRANS) supply path through CB2: This alternate voltage connection is used only on 230 V supplies. It isn't in parallel with the 460 V path in normal operation.